Mouthpieces for babies and small children, for example teats and suction nipples for bottles, are usually manufactured from a soft elastic parent material. By way of example, elastomers such as silicone or silicone rubber are used for this purpose.
These mouthpieces have to comply with stringent quality requirements, since they are exposed to considerable mechanical stresses. To prevent undesired swallowing of small parts, the design of the mouthpieces must in principle make it impossible for sections to be bitten off by the child. This demands high ultimate tensile strength. In addition, all of the ingredients have to comply with stringent toxicological requirements, and there must be no migration or release of ingredients. Although in polymer chemistry there are well-known additives which increase strength, their admixture to elastomers for mouthpieces of this type is often not permitted.
DE 20 2005 011 043 therefore proposes that these items for sucking and chewing be manufactured from an elasto-meric material which has at least one liquid-crystalline pigment (LC pigment) incorporated for reinforcement.
WO 2007/005427 proposes incorporating network-like reinforcing agents into the suction nipple.
EP 1 666 534 describes a process for the production of fibre-reinforced silicone rubber mouldings by vulcanizing liquid silicones in the presence of short and/or long fibers. The fibres used comprise natural fibres, aramid fibres, carbon fibres or synthetic fibres or a mixture thereof. Synthetic fibre materials mentioned comprise acetate fibres, polyamide fibres, polyester fibres, polyolefin fibres, polyvinyl alcohol fibres and polyurethane fibers. These mouldings are suitable as membranes or seals, and for sheathing and as protective covers, but not for the use mentioned in the sector of babies and small children. The admixture of glass fibres proposed in U.S. Pat. No. 6,010,656 is also unsuitable for the production of mouthpieces.
EP 1 293 323 discloses a process for injection moulding of liquid silicone rubber for the production of suction mouthpieces for babies' bottles and mouthpieces of anaesthesia machines, the intention here being to achieve better mixing of the components. This is achieved by passing a multiple amount of the necessary material through the mixer into a reservoir, and discharging progressively from the reservoir into the injection unit of the injection moulding machine.